1. Field of the Invention
The present invention relates to a syringe, and more particularly to a safety syringe that can safely hold a used needle and prevent the syringe from being used more than once.
2. Description of Related Art
A conventional syringe has a hollow barrel, a plunger and a needle hub. The needle hubs of conventional syringes are easily inclined during use so the needle hubs are difficult to retract into the barrel. Due to contagious diseases, the needles of syringes and even the hollow barrels and plungers, should not be used again and should be discarded immediately after use. Also, to keep nurses, doctors or workers who deal with discarded syringes from getting injured or infected by used needles, a safety syringe is needed. The conventional safety syringe often has a complex structure, so to provide a simple and effective safe design for the needles of syringes is still needed.
To overcome the shortcomings with conventional syringes, the present invention provides a safety syringe to mitigate or obviate the aforementioned problem.
The primary objective of the present invention is to provide a safety syringe that has a simpler structure than the conventional safety syringe and improves safety. The safety syringe in accordance with the present invention comprises a hollow barrel, a cord, a needle hub, a plunger and a plunger lock.
The hollow barrel has a distal open end, a proximal open end, a distal annular rib and a central annular rib. The needle hub is detachably mounted inside the proximal open end of the hollow barrel. The plunger has a push rod and a seal mounted on the push rod and is slidably mounted inside the hollow barrel. The cord connects to the needle hub and the seal.
When using the safety syringe, the plunger can pull the cord connected to the needle hub, so the needle hub can be pulled inside the hollow barrel to keep the used needle from injuring or infecting a person.